<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
		  // var myname = prompt('请输入名字');
		  // alert(myname);
		   var a=10;
		   a++;
		   console.log(a);
		   var b=10;
		   ++b;
		  console.log(b);
		   var e=10;
		   var f=e++ + ++e + e++ + ++e;  //1 e++=10 e=11 2 e=12 e++=12
		   console.log(f);               //3 e++=12 e=13 4 e=14 e++=14 
		   console.log(e);               // 10+12+12+14=48 e=14
		   var e=20;
		   var f=e++ + ++e + e++ + ++e;  //1 e++=20 e=21 2 e=22 ++e=22
		   console.log(f);               //3 e++=22 e=23 4 e=24 ++e=24
		   console.log(e);               //20+22+22+24=88 e=24
		</script>
	</head>
	<body>
	</body>
</html>
